Clare Bradley, Jan Mitchell, Alison Woodcock, James Wolffsohn, Stephen J Anderson, Timothy Ffytche, Martin Rubinstein and Winfried Amoaku (2008)
The MacDQoL individualized measure of the impact of macular degeneration on quality of life: reliability and responsiveness. American Journal of Ophthalmology, 146 (3). pp. 447-454. ISSN 0002-9394
Full text access: Open
PURPOSE: To investigate the MacDQoL test-retest reliability and sensitivity to change in vision over a period of one year in a sample of patients with age-related macular degeneration (AMD). DESIGN: A prospective, observational study. METHOD: Patients with AMD from an ophthalmologist's list (n = 135) completed the MacDQoL questionnaire by telephone interview and underwent a vision assessment on two occasions, one year apart. RESULTS: Among participants whose vision was stable over one year (n = 87), MacDQoL scores at baseline and follow-up were highly correlated (r = 0.95; P < .0001). Twelve of the 22 scale items had intraclass correlations of >.80; only two were correlated <.7. There was no difference between baseline and follow-up scores (P = .85), indicating excellent test-retest reliability. Poorer quality of life (QoL) at follow-up, measured by the MacDQoL present QoL overview item, was associated with deterioration in both the better eye and binocular distance visual acuity [VA] (r = 0.29; P = .001, r = 0.21; P = .016, respectively; n = 135). There was a positive correlation between deterioration in the MacDQoL average weighted impact score and deterioration in both binocular near VA and reading speed (r = 0.20; P = .019, r = 0.18; P = .041, respectively; n = 135). CONCLUSION: The MacDQoL has excellent test-retest reliability. Its sensitivity to change in vision status was demonstrated in correlational analyses. The measure indicates that the negative impact of AMD on QoL increases with increasing severity of visual impairment.
This is a Draft version
This version's date is:
is peer reviewed
Deposited by () on
in Royal Holloway Research Online.Last modified on 19-May-2011
(C) 2008 Elsevier whose permission to mount this version for private study and research is acknowledged. The repository version is the author's final draft.
1 J. Evans and R. Wormald, Is the incidence of registrable age-related macular degeneration increasing?, Br J Ophthalmol 80 (1996), pp. 9-14.
2 J.R. Evans, A.E. Fletcher and R.P. Wormald, Age-related macular degeneration causing visual impairment in people 75 years or older in Britain: an add-on study to the Medical Research Council Trial of Assessment and Management of Older People in the Community, Ophthalmology 111 (2004), pp. 513-517.
3 A. Chopdar, U. Chakravarthy and D. Verma, Age-related macular degeneration, BMJ 326 (2003), pp. 485-488.
4 P.K. Kaiser and D.V. Do, Ranibizumab for the treatment of neovascular AMD, Int J Clin Pract 61 (2007), pp. 501-509.
5 R.A. Williams, B.L. Brody, R.G. Thomas, R.M. Kaplan and S.I. Brown, The psychosocial impact of macular degeneration, Arch Ophthalmol 116 (1998), pp. 514-520.
6 J. Mitchell, P. Bradley, S.J. Anderson, T. ffytche and C. Bradley, Perceived quality of healthcare in macular disease: a survey of members of the Macular Disease Society, Br J Ophthalmol 86 (2002), pp. 777-781.
7 J. Mitchell and C. Bradley, Design of an individualized measure of the impact of macular disease on quality of life (the MacDQoL), Qual Life Res 13 (2004), pp. 1163-1175.
8 J. Mitchell, J.S. Wolffsohn and A. Woodcock et al., Psychometric evaluation of the MacDQoL individualized measure of the impact of macular degeneration on quality of life, Health Qual Life Outcomes 3 (2005), p. 25.
9 M.R. De Boer, A.C. Moll, H.C. de Vet, C.B. Terwee, H.J. Volker-Dieben and G.H. van Rens, Psychometric properties of vision-related quality of life questionnaires: a systematic review, Ophthalmic Physiol Opt 24 (2004), pp. 257-273.
10 F.L. Ferris, A. Kassoff, G.H. Bresnick and I. Bailey, New visual acuity charts for clinical research, Am J Ophthalmol 94 (1982), pp. 91-96.
11 S.J. Ahn, G.E. Legge and A. Luebker, Printed cards for measuring low-vision reading speed, Vision Res 35 (1995), pp. 1939-1944.
12 D.G. Pelli, J.G. Robson and A.J. Wilkins, The design of a new letter chart to measure contrast sensitivity, Clin Vision Sci 2 (1988), pp. 187-199.13 C.B. Engler, B. Sander, P. Koefoed, M. Larsen, T. Vinding and H. Lundandersen, Interferon alpha-2A treatment of patients with subfoveal neovascular macular degeneration-a pilot investigation, Acta Ophthalmol (Copenh) 71 (1993), pp. 27-31. (19)
14 D.A. Atchison, K.J. Bowman and A.J. Vingrys, Quantitative scoring methods for D15 panel tests in the diagnosis of congenital colour-vision deficiencies, Optom Vis Sci 68 (1991), pp. 41-48. (14)
15 H. Bartlett, L.N. Davies and F. Eperjesi, Reliability, normative data, and the effect of age-related macular disease on the Eger Macular Stressometer photostress recovery time, Ophthalmic Physiol Opt 24 (2004), pp. 594-599. (7)
16 I.L. Bailey, M.A. Bullimore, T.W. Raasch and H.R. Taylor, Clinical grading and the effects of scaling, Invest Ophthalmol Vis Sci 32 (1991), pp. 422-432. (226)
17 H. Coolican, Research methods and statistics in psychology, Hodder and Stoughton, London, England (1999), p. 280.
18 I.U. Scott, O.D. Schein, S. West, K. Bandeen-Roche, C. Enger and M.F. Folstein, Functional status and quality of life measurement among ophthalmic patients, Arch Ophthalmol 112 (1994), pp. 329-335. (126)
19 G.C. Brown, M.M. Brown and S. Sharma, Difference between ophthalmologists' and patients' perceptions of quality of life associated with age-related macular degeneration, Can J Ophthalmol 35 (2000), pp. 127-133. (84)
20 Mitchell J, Bradley C. The MacDQoL individualized measure of the impact of macular disease on quality of life. In: Preedy VA, editor. Handbook of disease burdens and quality of life measures. Heidelberg: Springer-Verlag. Forthcoming.
21 C. Bradley, Importance of differentiating health status from quality of life, Lancet 357 (2001), pp. 7-8. (78)